import logging

import agent_util
import jpype
from jpype import java, javax

logger = logging.getLogger(__name__)


class TomcatJMXPlugin(agent_util.Plugin):
    """Tomcat Plugin for the FortiMonitor Agent using JMX to collect data."""
    textkey = 'tomcat_jmx'
    label = 'Tomcat (JMX)'

    JMX_MAPPING = {

        # Memory
        'memory.heap': ('Heap Memory Usage Used', 'java.lang', 'Memory', None, 'HeapMemoryUsage', 'used', 'bytes'),
        'memory.heap.committed': ('Heap Memory Usage Committed', 'java.lang', 'Memory', None, 'HeapMemoryUsage', 'committed', 'bytes'),
        'memory.heap.init': ('Heap Memory Usage Init', 'java.lang', 'Memory', None, 'HeapMemoryUsage', 'init', 'bytes'),
        'memory.heap.max': ('Heap Memory Usage Max', 'java.lang', 'Memory', None, 'HeapMemoryUsage', 'max', 'bytes'),
        'memory.non_heap': ('Non-Heap Memory Usage Used', 'java.lang', 'Memory', None, 'NonHeapMemoryUsage', 'used', 'bytes'),
        'memory.non_heap.committed': ('Non-Heap Memory Usage Committed', 'java.lang', 'Memory', None, 'NonHeapMemoryUsage', 'committed', 'bytes'),
        'memory.non_heap.init': ('Non-Heap Memory Usage Init', 'java.lang', 'Memory', None, 'NonHeapMemoryUsage', 'init', 'bytes'),
        'memory.non_heap.max': ('Non-Heap Memory Usage Max', 'java.lang', 'Memory', None, 'NonHeapMemoryUsage', 'max', 'bytes'),

        # Threading
        'threading.count': ('Thread Count', 'java.lang', 'Threading', None, 'ThreadCount', None, 'count'),

        # OS
        'os.cpu_load.process': ('OS Process CPU Load', 'java.lang', 'OperatingSystem', None, 'ProcessCpuLoad', None, 'percent'),
        'os.cpu_load.system': ('OS System CPU Load', 'java.lang', 'OperatingSystem', None, 'SystemCpuLoad', None, 'percent'),
        'os.open_file_descriptors': ('OS Open File Descriptor Count', 'java.lang', 'OperatingSystem', None, 'OpenFileDescriptorCount', None, 'count'),

        # Class loading
        'class_loading.loaded_classes': ('Loaded Class Count', 'java.lang', 'ClassLoading', None, 'LoadedClassCount', None, 'count'),

        # MemoryPool
        'memory_pool.eden': ('Eden Space', 'java.lang', 'MemoryPool', 'Eden Space', 'Usage', 'used', 'bytes'),
        'memory_pool.eden.ps': ('PS Eden Space', 'java.lang', 'MemoryPool', 'PS Eden Space', 'Usage', 'used', 'bytes'),
        'memory_pool.eden.par': ('Par Eden Space', 'java.lang', 'MemoryPool', 'Par Eden Space', 'Usage', 'used', 'bytes'),
        'memory_pool.eden.g1': ('G1 Eden Space', 'java.lang', 'MemoryPool', 'G1 Eden Space', 'Usage', 'used', 'bytes'),

        'memory_pool.survivor': ('Survivor Space', 'java.lang', 'MemoryPool', 'Survivor Space', 'Usage', 'used', 'bytes'),
        'memory_pool.survivor.ps': ('PS Survivor Space', 'java.lang', 'MemoryPool', 'PS Survivor Space', 'Usage', 'used', 'bytes'),
        'memory_pool.survivor.par': ('Par Survivor Space', 'java.lang', 'MemoryPool', 'Par Survivor Space', 'Usage', 'used', 'bytes'),
        'memory_pool.survivor.g1': ('G1 Survivor Space', 'java.lang', 'MemoryPool', 'G1 Survivor Space', 'Usage', 'used', 'bytes'),

        'memory_pool.old.ps': ('PS Old Gen', 'java.lang', 'MemoryPool', 'PS Old Gen', 'Usage', 'used', 'bytes'),
        'memory_pool.old.cms': ('CMS Old Gen', 'java.lang', 'MemoryPool', 'CMS Old Gen', 'Usage', 'used', 'bytes'),
        'memory_pool.old.g1': ('G1 Old Gen', 'java.lang', 'MemoryPool', 'G1 Old Gen', 'Usage', 'used', 'bytes'),

        # Garbage Collector
        'gc.young.copy': ('Copy', 'java.lang', 'GarbageCollector', 'Copy', 'CollectionCount', None, 'count'),
        'gc.young.ps_scavenge': ('PS Scavenge', 'java.lang', 'MemoryPool', 'PS Scavenge', 'CollectionCount', None, 'count'),
        'gc.young.par_new': ('ParNew', 'java.lang', 'GarbageCollector', 'ParNew', 'CollectionCount', None, 'count'),
        'gc.young.g1_generation': ('G1 Young Generation', 'java.lang', 'GarbageCollector', 'G1 Young Generation', 'CollectionCount', None, 'count'),

        'gc.mixed.g1_generation': ('G1 Mixed Generation', 'java.lang', 'GarbageCollector', 'G1 Mixed Generation', 'CollectionCount', None, 'count'),

        'gc.old.mark_sweep_compact': ('MarkSweepCompact', 'java.lang', 'GarbageCollector', 'MarkSweepCompact', 'CollectionCount', None, 'count'),
        'gc.old.ps_mark_sweep': ('PS MarkSweep', 'java.lang', 'GarbageCollector', 'PS MarkSweep', 'CollectionCount', None, 'count'),
        'gc.old.concurrent_mark_sweep': ('ConcurrentMarkSweep', 'java.lang', 'GarbageCollector', 'ConcurrentMarkSweep', 'CollectionCount', None, 'count'),
        'gc.old.g1_generation': ('G1 Old Generation', 'java.lang', 'GarbageCollector', 'G1 Old Generation', 'CollectionCount', None, 'count'),
    }

    @staticmethod
    def __get_object_name_from_tuple(tuple_):
        """returns a constructed ObjectName.

        :type tuple_:  tuple (label, domain, type, bean_name, attribute_name,
        composite_data_key, unit)
        :param tuple_: A tuple with all the information for an ObjectName. A
        string that represents the label, a string that represents the domain,
        and so on and so forth.

        :rtype: javax.management.ObjectName
        :return: An ObjectName object that can be used to lookup a MBean.
        """
        domain, type_, bean_name = tuple_[1], tuple_[2], tuple_[3]
        canonical_name = "%s:" % domain

        if bean_name:
            canonical_name += "name=%s," % bean_name

        if type_:
            canonical_name += "type=%s" % type_

        return javax.management.ObjectName(canonical_name)

    @classmethod
    def get_connections_from_config(cls, config):
        """
        Parse the config object to build a structure of connections parameters
        based on the number of entries that are in each key. The main parameter we base on
        to split off is host.

        :type config: dict (host, port, username, password, jvm_path)
        :param config: Dictionary with the information stored in the config file.

        :rtype: Dict
        :return: Dictionary with connection information split up in multiple if needed.
        """
        keys = ['host', 'port', 'username', 'password', 'jvm_path']
        data = {}
        for key in keys:
            key_value = config.get(key)
            if not key_value and key not in ('username', 'password'):
                raise ValueError('Missing %s information from config' % key)
            elif not key_value and key in ('username', 'password'):
                # Username and password are not required
                continue
            else:
                values = [value.strip(' ') for value in key_value.split(',')]
                data[key] = values

        connections = {}
        hosts = data['host']
        for index, host in enumerate(hosts):
            connections[index] = {
                'host': host,
            }
            for key in ['port', 'username', 'password', 'jvm_path']:
                if len(data.get(key, [])) > 1:
                    # Multiple entries in this config, use the index to apply.
                    value = data[key][index]
                elif len(data.get(key, [])) == 1:
                    value = data[key][0]
                elif key not in ('username', 'password'):
                    raise ValueError('Missing %s information from config' % (key))
                else:
                    # Username and password can be skipped
                    continue
                connections[index][key] = value
        return connections

    @classmethod
    def __get_connection(cls, config):
        """
        returns a list of connections from the jpype library - a python interface to
        the Java Native Interface. Wheter there are 1 or many connections depends on the
        number of entries in the host, port and optionally username/password/jvm entries.

        :type config: dict
        :param config: Mapping of information under the application block for
         this plugin.

        :rtype: tuple (status, connection, error_message)
        :return: A tuple containing a numeric value corresponding to the
        agent_util status'. A MBeanServerConnection object. And, a string with
        an error message if any.
        """
        status = agent_util.SUPPORTED
        msg = None

        # Check that we have an agent config
        if not config:
            msg = "No JMX configuration found"
            cls.log.info(msg)
            status = agent_util.MISCONFIGURED

        # Make sure at least host and port are in the config
        if "host" not in config or "port" not in config:
            msg = ("Missing value in the [%s] block of the agent config file"
                   " (e.g host, port).") % cls.textkey
            cls.log.info(msg)
            status = agent_util.MISCONFIGURED

        # Try and get the jvm path from the config
        jvm_path = config.get('jvm_path')

        # If we can't find it then try and use the default
        if not jvm_path:
            try:
                jvm_path = jpype.getDefaultJVMPath()
                if not jvm_path:
                    status = agent_util.MISCONFIGURED
                    msg = ("Unable to find JVM, please specify 'jvm_path' in"
                           " the [%s] block of the agent config file.") % cls.textkey
                    cls.log.info(msg)

            except:
                status = agent_util.MISCONFIGURED
                msg = ("Unable to find JVM, please specify 'jvm_path' in the"
                       " [%s] block of the agent config file.") % cls.textkey
                cls.log.info(msg)

        try:
            # If the JVM has not been started try and start it
            if status is agent_util.SUPPORTED and not jpype.isJVMStarted():
                jpype.startJVM(jvm_path)

        except:
            status = agent_util.MISCONFIGURED
            msg = "Unable to access JMX metrics because JVM cannot be started."
            cls.log.info(msg)

        if status is agent_util.SUPPORTED:
            try:
                # Start the JVM if its not started
                # XXX: Redundant logic - is this necessary?
                if not jpype.isJVMStarted():
                    jpype.startJVM(jvm_path)

                j_hash = java.util.HashMap()

                # If we have a username and password use it as our credentials
                if config.get('username') and config.get('password'):
                    j_array = jpype.JArray(java.lang.String)(
                        [config.get('username'), config.get('password')])

                    j_hash.put(
                        javax.management.remote.JMXConnector.CREDENTIALS,
                        j_array)

                url = "service:jmx:rmi:///jndi/rmi://%s:%s/jmxrmi" % (
                    config.get('host'), int(config.get('port')))

                jmx_url = javax.management.remote.JMXServiceURL(url)
                jmx_soc = javax.management.remote.JMXConnectorFactory.connect(
                    jmx_url, j_hash)

                connection = jmx_soc.getMBeanServerConnection()

                return status, connection, None
            except Exception:
                msg = ("Unable to access JMX metrics, JMX is not running or"
                       " not installed.")
                cls.log.exception(msg)

        return status, None, msg

    @classmethod
    def get_metadata(cls, config):
        """returns a json object who's textkeys correspond to a given metric
        available on the JVM.

        :type config: dict
        :param config: Mapping of information under the application block for
         this plugin.

         :return: JSON Object for all metrics
        """
        result = {}
        configs = cls.get_connections_from_config(config)
        connections = {}
        errors = []
        for entry in configs.values():
            status, connection, msg = cls.__get_connection(entry)
            connection_key = "%s:%s" % (entry['host'], entry['port'])
            if msg:
                errors.append('%s %s' % (connection_key, msg))
            else:
                connections[connection_key] = connection
        if not connections.keys():
            cls.log.info('Unable to connect to any connection')
            for msg in errors:
                cls.log.error(msg)
            return result
        else:
            status = agent_util.SUPPORTED
            msg = ''

        for error in errors:
            cls.log.warning(error)

        for key, tuple_ in cls.JMX_MAPPING.items():
            object_name = cls.__get_object_name_from_tuple(tuple_)

            # Check to see if the object exists, if it doesnt we will throw
            # an error which will be handled silently by continuing through
            # the for loop.
            options = []
            for connection_key, connection in connections.items():
                try:
                    connection.getObjectInstance(object_name)
                    options.append(connection_key)
                except Exception:
                    cls.log.exception("Tomcat (JMX) plugin - %s bean not found at %s." % (object_name, connection_key))
                    continue

            if len(connections.keys()) >= 1 and not options:
                # No connection was able to get this value. Set it to unsupported.
                options = None
                status = agent_util.UNSUPPORTED
                msg = 'Unreachable %s at any connection' % key
            else:
                # We found options. Is supported.
                msg = ''
                status = agent_util.SUPPORTED

            label, unit = tuple_[0], tuple_[6]
            result[key] = {
                "label": label,
                "options": options,
                "status": status,
                "error_message": msg,
                "unit": unit
            }
        return result

    @classmethod
    def check(cls, textkey, data, config):
        """returns a value for the metric.

        :type textkey: string
        :param textkey: Canonical name for a metric.

        :type data: string
        :param data: Specific option to check for.

        :type config: dict
        :param config: Mapping of information under the application block for
         this plugin.

        :rtype: double
        :return: Value for a specific metric
        """
        entries = cls.get_connections_from_config(config)
        if data:
            for entry in entries.values():
                possible_match = "%s:%s" % (entry['host'], entry['port'])
                if possible_match == data:
                    config = entry
        else:
            # Default to the first configuration
            config = entries[0]
        status, connection, msg = cls.__get_connection(config)
        if msg:
            cls.log.info("Failed to get a connection: %s" % msg)
            return None

        tuple_ = cls.JMX_MAPPING.get(textkey)

        attribute_name, composite_data_key = tuple_[4], tuple_[5]

        # Create an ObjectName object to lookup
        object_name = cls.__get_object_name_from_tuple(tuple_)

        try:

            object_instance = connection.getObjectInstance(object_name)

            attribute_value = connection.getAttribute(
                object_instance.getObjectName(),
                attribute_name)

            attribute_class_name = attribute_value.__class__.__name__

            # If the object returned is just a numeric value
            if "CompositeDataSupport" not in attribute_class_name:
                return attribute_value.floatValue()

            # If the attribute object does not have the composite data key
            # return none
            if not attribute_value.containsKey(composite_data_key):
                return None

            # If the object returned is of type CompositeDataSupport return the
            # correct value from that object
            check_result = attribute_value.get(composite_data_key)

            return check_result.floatValue()
        except:
            cls.log.info(
                "Tomcat (JMX) plugin - %s bean not found." % object_name)
            return 0